Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In many older patients we observed a layer of subtle opacification on the anterior lens capsule, appearing as a ground glass film biomicroscopically. This precapsular film (PCF) could be uniform but often had radial grey lines in the mid zone, holes in the paracentral region, and was occasionally rolled up in strings. Lens capsular material obtained at cataract extraction was studied in patients with and without the film. By scanning electron microscopy the PCF appeared as a friable, incomplete fibrillar layer, with rolling of the edges suggesting loose attachment. Ultrastructurally its component fibrils were from 3-6 nm in diameter, similar to the finer fibrils in pseudoexfoliation (PSX) material. Life PSX material the layer stained positively for the elastic microfibril-associated protein, fibrillin, in a lens with radial striations. These similarities suggested that the two conditions have some relationship and that the PCF may be a precursor of PSX. Finding patches of the fibrillar network in some control patients implies that the PCF is common in patients of cataract age, though seldom detected clinically.
 ...
PMID:Precapsular film on the aging human lens: precursor of pseudoexfoliation? 227 34

Weill-Marchesani syndrome (WMS) is a rare condition characterized by short stature, brachydactyly, joint stiffness, and characteristic eye abnormalities including microspherophakia, ectopia of lens, severe myopia, and glaucoma. Both autosomal recessive (AR) and autosomal dominant (AD) modes of inheritance have been described for WMS. A locus for AR WMS has recently been mapped to chromosome 19p13.3-p13.2 while mutation within the fibrillin-1 gene (15q21.1) was found in one AD WMS family. In order to answer the question of whether or not genetic heterogeneity could be related to a clinical heterogeneity, we reviewed 128 WMS patients from the literature (including 57 AR, 50 AD, and 21 sporadic cases), with a particular attention to clinical features. Statistical analyses using Fischer exact test were used to compare the proportions of 12 clinical parameters between AR and AD patients. There was no significant difference between both groups for myopia, glaucoma, cataract, short stature, brachydactyly, thick skin, muscular build, and mental retardation. Significant results were found for microspherophakia (94% in AR, 74% in AD, Fischer 0.007), ectopia lentis (64% in AR, 84% in AD, Fischer 0.016), joint limitations (49% in AR, 77% in AD, Fischer 0.010), and cardiac anomalies (39% in AR, 13% in AD, Fischer 0.004). Nevertheless, we failed to distinguish AR from AD inheritance in individual cases. These results support the clinical homogeneity but the genetic heterogeneity of WMS.
 ...
PMID:Clinical homogeneity and genetic heterogeneity in Weill-Marchesani syndrome. 1459 50

Pseudoexfoliation syndrome is an ocular manifestation of a systemic elastosis. Exact etiology of this condition remains unknown. The basic pathogenetic concept of PEX is a pathological process of the extracellular matrix, characterized by the excessive production of an abnormal extracellular material which aggregates and accumulates and is not degraded in vivo. This material is produced primarily by the non pigmented epithelium of the ciliary body, the posterior iris pigment epithelium, and the preequatorial lens epithelium, while the corneal endothelium, trabecular cells, and vascular endothelia and smooth muscle cells of the iris have also been implicated. PEX material has a complex glycoprotein/proteoglycan, composition containing glycosaminoglycans (heparan sulfate, chondroitin sulfate, dermatan sulfate, hyaluronic acid). The prevailing presence of elastic fiber epitopes, mainly elastic microfibrillar components (elastin, vitronectin, amyloid P, fibrillin-1, LTBP-1), has led to the current theory explaining PEX as a type of elastosis, affecting especially elastic microfibrils. Ocular deposition of pseudoexfoliation material can lead to many complications in intraocular surgery like increased risk of zonular dehiscence, capsular rupture, vitreous loss during cataract extraction. Special attention is required before, during and after surgery.
 ...
PMID:[Pseudoexfoliation syndrome--etiopatogenesis and clinical course]. 1688 48

Exfoliation syndrome (XFS) is an age-related, generalized disorder of the extracellular matrix characterized by the production and progressive accumulation of a fibrillar extracellular material in many ocular tissues and is the most common identifiable cause of open-angle glaucoma worldwide. XFS plays an etiologic role in open-angle glaucoma, angle-closure glaucoma, cataract, and retinal vein occlusion. It is accompanied by an increase in serious complications at the time of cataract extraction, such as zonular dialysis, capsular rupture, and vitreous loss. It is associated systemically with an increasing number of vascular disorders, hearing loss, and Alzheimer's disease. XFS appears to be a disease of elastic tissue microfibrils. The characteristic fibrils, composed of microfibrillar subunits surrounded by an amorphous matrix comprising various glycoconjugates, contain predominantly epitopes of elastic fibers, such as elastin, tropoelastin, amyloid P, vitronectin, and components of elastic microfibrils, such as fibrillin-1, fibulin-2, vitronectin, microfibril-associated glycoprotein (MAGP-1), and latent TGF-beta binding proteins (LTBP-1 and LTBP-2), the proteoglycans syndecan and versican, the extracellular chaperone clusterin, the cross-linking enzyme lysyl oxidase, and other proteins. A recent milestone study showed that two common single nucleotide polymorphisms in the coding region of the lysyl oxidase-like 1 (LOXL1) gene located on chromosome 15 were specifically associated with XFS and XFG. LOXL1 is a member of the lysyl oxidase family of enzymes, which are essential for the formation, stabilization, maintenance, and remodeling of elastic fibers and prevent age-related loss of elasticity of tissues. LOXL1 protein is a major component of exfoliation deposits and appears to play a role in its accumulation and in concomitant elastotic processes in intra- and extraocular tissues of XFS patients. This discovery should open the way to new approaches and directions of therapy for this protein disorder.
 ...
PMID:The management of exfoliative glaucoma. 1892 11

Marfan syndrome is an autosomal dominant genetic connective tissue disorder that results from mutations in the fibrillin-1 gene located on chromosome band 15q15-21. Fibrillin, a glycoprotein, is widely expressed throughout the body and contributes to the elasticity and force-bearing capacity of connective tissue. In the eye, fibrillin is a key constituent of the ciliary zonules, which suspend the crystalline lens in place. The zonular defect leads to ectopia lentis, which is a hallmark of Marfan ocular abnormalities and occurs in 60% to 80% of cases. Other less common ocular features of Marfan syndrome are increased axial length, astigmatism, and flat cornea. Visual function in Marfan syndrome could be affected in several ways: ectopia lentis, refractive error, amblyopia, retinal detachment, cataract, and glaucoma. Management of a subluxated lens starts with the correction of refractive error with eyeglasses in mild cases. In more severe cases, especially when the lens bisects the pupil, complete correction of refractive error is impossible without removing the subluxated lens. The best method for visual rehabilitation after lens extraction is still debated. Aphakic Artisan lens implantation at the time of subluxated lens removal results in good visual outcomes with an acceptable safety profile. Studies with longer term follow-up and larger sample populations are needed to evaluate the safety of this procedure in patients with Marfan syndrome.
 ...
PMID:Management Strategies of Ocular Abnormalities in Patients with Marfan Syndrome: Current Perspective. 3082 Feb 90

A 53-year-old male with newly diagnosed acromegaly came to our clinic with the chief complaint of diplopia. He had the past ocular history of uneventful phacoemulsification cataract surgery with intraocular lens (IOL) implantation in the right eye 17 years ago and left eye 15 years ago. Postoperative examination showed remarkable improvement in visual acuity. Two years ago, he developed elevated intraocular pressure (IOP) in both eyes, which was well-controlled with the use of travoprost 0.004%/timolol 0.5%. At the clinic, slit-lamp examination revealed inferiorly subluxated IOL bilaterally. The patient received IOL repositioning with pars plana vitrectomy and scleral fixation in the left eye smoothly. We hypothesize that excess growth hormone is associated with dysregulation of fibrillin, resulting in zonular weakness, which causes late bilateral IOL subluxation. Elevated IOP may also be related to acromegaly. To the best of our knowledge, this is the first report to describe the association between IOL subluxation and acromegaly.
 ...
PMID:Late spontaneous bilateral intraocular lens subluxation accompanied with intraocular pressure elevation in a patient with acromegaly. 3287 48